Mini Recycled Greenhouse

Introduction: Mini Recycled Greenhouse

A DIY recycled Greenhouse made from those nasty styrofoam egg cartons.

Step 1: What to Do...

With having ducks and chickens that produce eggs for resale, the obvious need for egg cartons is there. So trying to keep costs down I frequent craigslist for extra "free" cartons. Most of the time I get the paper fiber cartons, but occasionally there are the Styrofoam ones that get mixed in. I was searching for a good use for them and it hit me while i was buying new pellets for my 72 pod "greenhouse"

i can make individual greenhouses

Step 2: Gather Materials

Time to get all the supplies you need,

  • filet knife
  • knife sharpener
  • masking tape
  • egg carton
  • plastic wrap

  1. mixing bucket
  2. Potting soil/ Starter soil/ Peat moss (i had 3 lbs left over from last season)
  3. Dried and crushed egg shells
  4. Coffee grinds

seeds, seeds and more seeds

Step 3: Good and Sharp

I choose to use a filet knife due to the blade thickness and sharpness. I needed to maintain the carton integrity and didn't want to lose too much. While it was easy to just cut the top off, that would have wasted more then I wanted.

Whichever blade you intend to use make sure it is good and sharp so it will cut easily through the styrofoam and not catch on any burrs

Step 4: Nip the Tip


On most of the cartons I received there is a lip at the very top of the cartons. This is what i decided to cut off as it would give me the most room for the canopy or "top" of the greenhouse. It was easy to start in a corner and SLOWLY work my way around, the knife was sharp that it cut the foam like warm butter, there was almost no resistance. Take your time and don't rush or you risk possibly cutting yourself with a extremely sharp knife. Remember it only takes 4 lbs of pressure to break skin, if you divide that by the thickness of the blade your working with it will be a minuscule amount of pressure required to cut.

Step 5: Canopy Setup

Using the plastic wrap, pull out a sufficient amount so that you can "double warp" the carton. I went about 4 inches past the end to overlap.

Step 6: Time to Mix It Up

Now we get a little dirty, dump the potting soil in first as it tends to be dusty (3 lbs), then I added the crushed egg shells (just over 1 1/2 lbs) and the coffee grinds on top (3 lbs) These have all been saved over the last few months inside in large containers after breakfast. With the harsh winter the NE has suffered I was not able to get to my compost pile. the shells were "cooked" in the microwave till they were dried out (about 3 mins) then crushed with a small wooden mallet like the ones sold as "crab mallets" saved in a old hot cocoa container, the coffee grinds were already semi-wet as they were kept in a sealed container.

I had to add about a quart of water to the mix as the potting soil was semi absorbent. You want the mix to be wet enough to hold it's shape but not so wet it's runny

Step 7: Assembly Time

now we get to put it all together

  1. Place your carton on your laid out plastic wrap
  2. Add some dirt mix to container, fill to just below the top of egg holder
  3. Poke in seed holes
  4. Add your desired seeds
  5. Cover with dusting of mix

Step 8: Wrap It Up

flip one side or the other of the plastic wrap over the top TIGHTLY you want to make the roof firm so the light can get through and the moisture and condense and drop back down inside.

fold the sides up and secure with a strip of masking tape and label accordingly

when it comes time to plant the seeds after they have sprouted you can pull off the plastic and plant the entire piece as one or break them up to spread out then you can save the cartons for next year and re-use them. This was a great weekend project to do with my 6 yr old as he planted his own seeds and can watch them grow. Then move them into our raised bed garden in a few weeks after they sprout.

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    6 years ago

    update from the time of posting this instructable all of my viable seeds have sprouted. i now have 7 cartons full of seedling's in another week or two they will be big and strong enough to be transplanted outside